Kick-offs and drop-outs restart the contest.

What these restarts are for

Kick-offs and drop-outs are controlled restarts. They put the ball back into play after a fixed event rather than leaving the next phase to a scrum, tap, penalty, free kick, or ordinary play-the-ball.

The practical difference is location and method. A kick-off is taken from the centre of halfway. A goal-line drop-out is taken by the defending team from the centre of its goal line. A 20-metre drop-out is a drop kick from the centre of the 20-metre line. A 20-metre optional kick also starts at the centre of the 20-metre line, but it may be kicked in any manner and in any direction.

Starting a half and restarting after points

The kick-off is a place kick from the centre of the halfway line. The team that loses the toss for choice of ends kicks off to start the first half, and the other team kicks off to start the second half. After points are scored, the team that conceded the points kicks off to restart play.

The kicker's team must stay behind the ball until it is kicked. Opponents must be at least 10 metres from the halfway line and may not advance early. The ball must be kicked in the prescribed manner and travel at least 10 metres forward into the field of play.

Why the ball must travel far enough

The 10-metre requirement gives both teams a fair restart contest. If the ball fails to travel 10 metres forward, if the kicker uses the wrong type of kick, or if the kick goes over touch, touch in-goal, or the dead-ball line on the full, the kicking team can be punished.

Players other than the kicker can also offend. A teammate who runs in front of the kicker, a receiver who comes too close before the kick, or a player who wilfully touches the ball before it has gone 10 metres can give away a penalty or, in some accidental cases, lead to a scrum or managed restart.

When a restart kick finds touch

A modern rugby league restart can reward a well-placed kick that bounces into touch. Under the international laws, if a kick-off, goal-line drop-out, 20-metre drop-out, or 20-metre optional kick finds touch other than on the full, the kicking team restarts with a play-the-ball on the 20-metre line opposite where the ball entered touch.

The captain of the kicking team can move that play-the-ball to a permitted position: the 10-metre mark from touch or centre field. This is why short or angled restart kicks are not just a way to recover possession in the air; they can also create a set attacking position if the ball legally finds touch.

When the optional kick is used

A 20-metre optional kick is used for several in-goal outcomes. Common examples include an attacking player last touching the ball before it goes dead or into touch in-goal, an attacking player accidentally infringing in the in-goal area, or a defending player catching an opponent's kick in general play on the full while in their own in-goal.

The optional kick is different from a drop-out. The ball may be kicked in any manner and in any direction, and it is in play as soon as it is kicked. The opposition must retire 10 metres from the 20-metre line and may not advance until the ball is kicked. The first tackle after a 20-metre optional kick is a zero tackle.

When the 20-metre restart must be a drop kick

A 20-metre drop-out is used when the ball goes dead in the opponents' in-goal from a penalty kick. It does not matter whether that penalty kick was an attempt at goal or another penalty kick that went dead. The defending team restarts with a drop kick from the centre of the 20-metre line.

This is easy to confuse with the 20-metre optional kick because both restart from the 20-metre line. The difference is the trigger and the method: the optional kick can be kicked any way, while the drop-out requires a drop kick.

When defenders drop out from their line

A goal-line drop-out is normally ordered when the defending team is responsible for the ball becoming dead in its own in-goal or when a defender is trapped there. Typical cases include a defender touching down, being tackled in-goal, last touching the ball before it goes dead or into touch in-goal, or accidentally infringing in the in-goal area.

It can also apply after a defender kicks the ball into touch on the full from their own in-goal, after certain accidental in-goal rebounds involving defenders, or when the ball is made dead by a defender straddling the dead-ball or touch-in-goal line. The result is a drop kick from the centre of the goal line, giving the attacking side a chance to receive possession back in good field position.

How referees treat short drop-outs

Some restart kicks are deliberately contestable. The international laws recognise contested goal-line and 20-metre drop-outs: high or bouncing cross-field kicks that give players from both teams a reasonable chance to play at the ball.

If that kind of contested drop-out does not travel 10 metres forward or goes into touch on the full, the restart can be a play-the-ball near the relevant restart line rather than the ordinary full penalty outcome. The important limit is intent and opportunity. The referee must be satisfied the kick was genuinely capable of being contested, and contact with the ball before it has a chance to travel 10 metres can still produce the stronger penalty result.

How the restart is enforced

Officials first decide why the ball became dead or why play stopped. That determines whether the correct restart is a kick-off, goal-line drop-out, 20-metre drop-out, 20-metre optional kick, scrum, handover, penalty, free kick, tap restart, or play-the-ball.

Once the restart is identified, the referee and touch judges manage the mark, check that the kick is taken from the right place and in the right manner, watch the 10-metre distance, and judge whether players have advanced early or interfered before they are entitled to play the ball.

Where people get caught

• "Every 20-metre restart is the same": no. A 20-metre optional kick and a 20-metre drop-out start from the same line but have different triggers and kicking methods.
• "A short kick-off is illegal": not if it still travels at least 10 metres forward into the field of play before it is played.
• "A ball bouncing into touch is always bad for the kicking team": not on covered restarts. If it finds touch other than on the full, the kicking team can receive the play-the-ball restart.
• "A drop-out is just a punt from the line": no. A drop-out is a drop kick, meaning the ball is dropped from the hands and kicked immediately after it rebounds from the ground.
• "The referee always penalises a failed short drop-out": not always. Contested restart provisions can replace the penalty with a play-the-ball outcome when the specific conditions are met.

How to read the restart

1. Ask what caused the stoppage: score, start of half, attacking in-goal error, defender caught in-goal, ball made dead, penalty kick dead, or restart kick into touch.
2. Identify the restart type and mark: halfway, goal line, 20-metre line, or a play-the-ball position after a legal restart kick into touch.
3. Check whether the kick must be a place kick, drop kick, or optional kick.
4. Watch whether the ball travels 10 metres forward and whether either team infringes before the ball is playable.
5. Apply the correct result: play on, zero tackle, play-the-ball restart, scrum for accidental interference, penalty, or another restart required by the sequence.

Source material

• International Rugby League Laws of the Game PDF
• Rugby Football League Laws of the Game
• International Rugby League
• NRL rules and interpretations